gremlin - 无法在 gremlin 控制台中使用 system.graphs() 列出图表

Question

所以我开始使用 janusgraph 和 gremlin。我遵循了本指南 https://developer.ibm.com/dwblog/2018/whats-janus-graph-learning-deployment/安装并在图上进行一些遍历。现在我想用 system.graphs() 列出 cassandra 数据库中的所有图表，但出现错误:

No such property: system for class: Script14
Type ':help' or ':h' for help.
Display stack trace? [yN]y
org.apache.tinkerpop.gremlin.groovy.plugin.RemoteException: No such property: system for class: Script14
        at org.apache.tinkerpop.gremlin.console.groovy.plugin.DriverRemoteAcceptor.submit(DriverRemoteAcceptor.java:175)
        at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:232)
        at org.apache.tinkerpop.gremlin.console.GremlinGroovysh.execute(GremlinGroovysh.groovy:99)
        at org.codehaus.groovy.tools.shell.Shell.leftShift(Shell.groovy:122)
        at org.codehaus.groovy.tools.shell.ShellRunner.work(ShellRunner.groovy:95)
        at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$2$work(InteractiveShellRunner.groovy)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1213)
        at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:132)
        at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:152)
        at org.codehaus.groovy.tools.shell.InteractiveShellRunner.work(InteractiveShellRunner.groovy:124)
        at org.codehaus.groovy.tools.shell.ShellRunner.run(ShellRunner.groovy:59)
        at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$2$run(InteractiveShellRunner.groovy)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1213)
        at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:132)
        at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:152)
        at org.codehaus.groovy.tools.shell.InteractiveShellRunner.run(InteractiveShellRunner.groovy:83)
        at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:232)
        at org.apache.tinkerpop.gremlin.console.Console.<init>(Console.groovy:166)
        at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:232)
        at org.apache.tinkerpop.gremlin.console.Console.main(Console.groovy:478)

我做错了什么以及如何解决这个问题？

Answer 1

Gremlin Server 或 JanusGraph 没有原生的 system 对象的概念，这就是您收到该错误的原因。服务器根本不知道该变量名指的是什么。

要获取图形名称列表，您必须使用 JanusGraph 的 ConfiguredGraphFactory ，此时语法为:

ConfiguredGraphFactory.getGraphNames()

您可以阅读更多相关信息 here在 JanusGraph 文档中，或参阅您提供的链接中的“验证 JanusGraph 部署上的测试数据”部分并从那里获取。